GEO — Generative Engine Optimization — is the discipline of optimizing your content to be cited inside AI-generated answers. It overlaps with traditional SEO but the target is different: instead of ranking #1 in the blue links, you're trying to be the source quoted in the AI Overview, the ChatGPT response, or the Perplexity citation.
GEO is distinct from AI Citability. AI Citability is about being extractable (can the AI parse you?). GEO is about being chosen (out of all the extractable pages, why should the AI cite yours?). The first is a technical baseline; the second is a content and authority strategy.
The core levers are entity associations (is your brand mapped to the topics you want to be cited for?), question-answer content structure (are your headings phrased the way people actually ask LLMs?), featured-snippet optimization (which feeds AI Overviews directly), and authority signals the LLMs weight heavily — Wikipedia, news coverage, and cross-domain brand mentions.